Controlfile Recovery Requires RESETLOGS

From: Jeremy Paul Schneider <jeremy.schneider_at_ardentperf.com>
Date: Wed, 9 May 2007 14:49:08 -0500
Message-ID: <18be0f260705091249y3788675ayd7d7a7e24ea78cbf@mail.gmail.com>

Hey all...

In response to a bit of discussion last week - I put together the test and output showing how controlfile recovery requires recovery and a RESETLOGS even if the database was closed normally, in a consistent state. I posted the output here:

http://www.ardentperf.com/2007/05/09/controlfile-recovery-requires-resetlogs/

Most questions can be answered by looking at the post since I walked through the whole process. But to answer a few specific questions that various people asked...

On 5/4/07, Mark W. Farnham <mwf_at_rsiz.com> wrote:

> 1) Did you shut down just the database or the whole machine?
>

In this test I only shut down the database however it was completely shutdown and I would anticipate the same results with a machine reboot.

2) Did you let Oracle complete the shutdown immediate, or did you
> kneecap any processes, especially including LGWR (log writer, whatever name
> it goes by on your release)?
>

Yes Oracle completed the shutdown immediate - it was a clean shutdown. I didn't kneecap anything.

> 3) Is any sort of write cache enabled on the devices supplying the
> persistent media for your redo logs or controlfiles?
>

Shouldn't be relevant for this test. The OS and storage subsystem were never interupted; I simply shutdown Oracle (normal) then removed the control files and restarted it.

4) Did you replace the current controlfile with anything else?
>

Nope. Just deleted it.

5) Did you use the recover command with … using backup controlfile?
>

Yes - oracle required the "using backup controlfile" clause.

On 5/4/07, Joel.Patterson_at_crowley.com <Joel.Patterson_at_crowley.com> wrote:
>
> Even if you switched current, or all before shutdown?
>

In the test I posted online I tried with a log switch before shutdown. I would anticipate that this has no impact either way on the RESETLOGS.

On 5/4/07, Hemant K Chitale <hkchital_at_singnet.com.sg> wrote:
>
>
> Question : In your recovery testing, what was the exact sequence ? Was
> it ?
> a) Restore an older controlfile binary backup -- only
> controlfile restored, datafiles being current
> b) Issue RECOVER DATABASE USING BACKUP CONTROLFILE -- did you
> also specify "UNTIL CANCEL" ?
>
> OR
> a) Create Controlfile
> b) Issue RECOVER DATABASE ... commands.

The first - I restored a binary backup.

-- 
Jeremy Schneider
Chicago, IL
http://www.ardentperf.com/category/technical
--
http://www.freelists.org/webpage/oracle-l

Received on Wed May 09 2007 - 14:49:08 CDT